1. Field of the Invention
This invention relates to process and composition for the treatment of fibers or articles fabricated therefrom, and more particularly to process and composition for imparting wettability to artificial fibers, and more specifically to polyethylene terephthalate fibers.
2. Description of the Prior Art
In the past, synthetic fibers have found widespread acceptance in industry and consumer use due to the strength, toughness and higher modulus of these fibers and the goods made therefrom. However, in spite of the positive features, there are also certain properties of synthetic fibers which are objectionable to the consumer. Among these, the fibers are generally hydrophobic and therefore unable to absorb and transport moisture and to dissipate static charge. They also exhibit a propensity to accept and to hold soil deposits. In addition, polyethylene terephthalate fibers, in particular, are difficult to dye with dispersed and water based dyes.
Prior practitioners have attempted to eliminate the negative aspects of synthetic fibers by approximation of natural fibers in their ability to interact with water. In the literature, there are several approaches to this problem: First, hydrophilic polymers are formed by polymerization of new monomers with pendant hydrophilic groups or by copolymerization of the existing monomers with new hydrophilic monomers. Secondly, hydrolysis of the surface of the fiber has been performed in order to form --OH groups on the surface. Also, grafting of hydrophilic units of the fiber surface has been attempted. Finally, polymeric, hydrophilic, water-insoluble finishes have been applied to finished goods made from the synthetic fiber.
The first approach is in fact a rejection of the existing fibers and requires preparation of a completely new fiber, which will result in considerable expense connected with the introduction of a new generic fiber on the market. The second approach, namely that of hydrolysis of the polymer surface, is a very delicate operation and may lead to a lower molecular weight species at the fiber surface, decreasing the stability of these species on washing. Deeper hydrolysis may result in partial degradation of the polymer and therefore further decrease the fiber strength.
Grafting of hydrophilic species such as acrylic acid on the fiber surface is a radical reaction usually initiated by gamma radiation or other high energy sources. The main disadvantage is a lower efficiency of radical formation on the polymer backbone and easy polymerization of acryclic acid into polyacrylic acid without any chemical bonding to the fiber surface.
Finally, the application of polymeric textile finishes normally leads to modifications of low durability on abrasion and usually creates a barrier to subsequent dyeing of the treated fabric. The application of a polymeric textile finish is therefore usually the last operation in manufacture of the final goods. Since the finishes are generally soft plastic polymers, they may serve as soil traps.